Describing Matter
Name one characteristic property of an element
Boiling Point
Melting Point
Chemical Activity
Density
What unit do you use to to measure volume?
cubic centimeter
What is a chemical bond?
the strong force that holds atoms together
What process is used to separate iron from its ores
By heating iron ore and a source of carbon
Why would a rock sink in water?
The rock is more dense that the water
What are properties that never change for a given substance
Characteristic properties
The amount of matter an object contains is its what?
Mass
What is an atom?
the smallest particle of an element
Any rock that contains a metal or other economically useful material
What is an example of a liquid?
water
What is a well-blended mixture that appears to be a single substance.
Solution
How do you find the volume of a rectangular object?
length x width x height
What is a pure substance that can't be broken down into any other substance by chemical means?
element
What is electrolysis used for?
Separate copper from its ore
What happens during a chemical change?
substances combine or break apart to make new substances
What are two specific examples of a chemical change?
burning leaves
rust
How do you measure density?
mass divided by volume
What is a molecule?
a group of atoms that are joined together and act as a single unit
using its density
What happens during a physical change?
the object changes its form but not its identity
What are two specific examples of physical change?
Melting, boiling, cutting, crushing, etc.
Why is weight not a constant measure of an object?
it depends the amount of gravity in the air.
What are 3 of Dalton's theories of atoms?
1. Atoms can't be broken into smaller pieces
2. In any elements, all atoms are alike. Atoms of different elements are different
3. Atoms of 2 or more elements form compounds
4. Atoms of each element have a unique mass. The mass is always in a constant ratio
How is panning done?
1. put mixture of gold, dirt and sand into a shallow pan
2. Cover it with water and shake it around
3. The water with the less dense dirt and sand get carried away
4. The more dense gold stays behind
If an object has a density of 1.38 g/cm, would it float or sink in water? Why?
It would sink because the density of water is 1.0 g/mL which means the object is denser than water and will sink.